APPLICATION OF THE FINITE-ELEMENT METHOD TO TIME-DEPENDENT QUANTUM-MECHANICS .1. H AND HE IN A LASER FIELD

A finite element approach is described to solve the time- dependent Hartree-Fock equation of atoms in the presence of time-dependent electromagnetic fields. Time-dependent energy changes, ionization rates and high order nonlinear optical polarizabilities, chi2n+1 (n greater-than-or-equal-to 0) for the atoms H and He have been calculated. The finite element method is shown to be easily adaptable to treat intense short pulses and includes automatically both bound and continuum electronic states.